SU1723039A1 - Method of separation of oxides of antimony (iii) and arsenic (iii) - Google Patents

Abstract

The invention relates to inorganic chemistry, in particular, to methods for the separation of antimony (III) oxides and arsenic (III) oxides, which are used as fungicides and zoocides in agriculture. The method is carried out as follows. In a flask with a Dean-Stark trap and reflux condenser, protected by a calcium chloride tube, suspension consisting of antimony (III) oxide, mouse, covalent anhydride, butyl alcohol, and heptane are boiled until the evolution of water (4 hours) is completely stopped. Alcohol is consumed, taking into account the content of mouse covalent anhydride in the mixture, and the ratio (by volume) of alcohol and heptane is 2: 1. After cooling the reaction mass, the alcohol-heptane phase is separated by filtration, the precipitate (3BaO3) is washed with heptane and dried to constant weight. The yield of antimony oxide is 99.3-100%. In order to regenerate the oxide of arsenic (III), the alcohol-heptane filtrate is hydrolyzed with bidistillate, filtered, the precipitate is washed with water and alcohol. The yield of dry oxide of arsenic (III) is 90.0-93.4%. The invention makes it possible to increase the yield of products: antimony oxide from 85% to 99.3-100%, and mouse oxide, from 60% to 90.0-93.4%. 1 tab. (Ls

Description

The invention relates to chemical technology of inorganic compounds, namely, to a method for the separation of antimony (III) oxides and arsenic (O which are naturally found together (for example, Algerian natural senarmontite (SbzOa) contains more than 4% mouse oxide (A $ 20)) ).

Oxides of arsenic (III) and antimony (III) are used as fungicides and zoocides in agriculture, veterinary medicine, and also as starting materials for the production of almost all mouse to antimony containing compounds.

The closest to the proposed technical essence and the achieved result is the method of separation of oxides of arsenic (III) and antimony (III) by their preliminary dissolution in concentrated hydrochloric acid, extraction of arsenic trichloride with benzene or toluene and subsequent complete hydrolysis of the corresponding chlorides separately. .

The essence of this method is as follows. The mouse to- and antimony-containing compounds, including oxides, is transferred into the solution by treatment with concentrated hydrochloric acid, from which the trichloride of the mouse is most selectively extracted with benzene and toluene. At a concentration of 10 m HCl (and above) the mouse is extracted with benzene almost quantitatively. Extraction equilibrium is established rapidly. Antimony (III) and other elements that form chloride complexes are not extracted under these conditions.

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as with such a high concentration of HCI, they form chloride metal acids that are not extracted by non-polar organic solvents. Antimony (III) and some other elements are significantly extracted from solutions with a lower concentration of HCI.

In order to regenerate the starting oxides, the antimony-containing extraction phase and the benzene (toluene) extract are hydrolyzed separately with water.

Thus, the goal is achieved by combining the following sequential chemical reactions and processes:

AS2O3 + 6HCI

SD203 + 6HCI

2AsCl3 + 3H20; + ЗН20;

extraction with benzene or toluene from hydrochloric acid solution;

2AsCl3 + 3HaO А82СЫ + 6НС1;

2SbCI3 + 3H20. 5b2O3 + 6HC1.

The yield of, for example, arsenic (III) oxide does not exceed 60% of the original mouse of cohesive anhydride, and the yield of Sb3O3 — 85%.

The main disadvantages of the known ATP are, both of which are multistep process and low product yield.

The aim of the invention is to increase the yield of products.

The goal is achieved in that according to the method of separation of oxides of antimony (III) and arsenic (III) by treating their mixture with chemical reagents followed by hydrolysis of the mouse-containing extract, filtering and drying the regenerated components, a mixture of butyl alcohol and heptane is used as chemical reagents, and the process is carried out at the boiling point of the suspension until the evolution of water is completely stopped.

The essence of the proposed method is that when processing a mixture of antimony (III) and arsenic (III) oxides with a mixture of butyl alcohol and heptane, arsenic (III) oxide is quantitatively dissolved in organics, and antimony (III) oxide also remains quantitatively at the bottom reactor. Therefore, for the extraction, the alcohol is taken with regard to the content of mouse forging anhydride in the mixture. Per mole of arsenic (III) oxide, 6.2 moles of butyl alcohol are optimal. The use of amyl and higher alcohols of a saturated series although leads to the complete extraction of arsenic from mixtures, however, this increases the solubility of antimony (III) oxide in them. In addition, higher homogeneous alcohols of the aliphatic series are less accessible and more expensive than butyl alcohols. Therefore, to separate the oxides of antimony and

The mouse should use H-butyl and isobutyl alcohols.

As a result of treatment with water of the organic extract, high purity arsenic (III) oxide is released. Its yield is high compared with the prototype and fluctuates within a limit of 90-93% of ax.

In this case, the corresponding alcohols and heptane are regenerated with a yield of 91-94% in

0 as an azeotropic mixture. The latter can be reused for re-extraction of the mouse from a new portion of the initial mixture, etc., the process becomes continuous cyclical.

5 The degree of extraction of the mouse also depends on the ratios of alcohol and heptane by volume. The optimal ratio (by volume) of alcohol and heptane is 2: 1. With an increase in the proportion of alcohol by 50%, for example, the degree of extraction of arsenic (III) oxide from the mixture decreases significantly (by 30-40%) and, conversely, when the volume of heptane is increased, for example, by 2 times compared with the volume ratio 2 : 1, although quantitatively

5 and the mouse augmented anhydride is removed, however, the duration of the process is increased by almost 2 hours, which is undesirable. In the first case, the release of water from the reaction medium is difficult because of its high solubility in butyl alcohol, i.e. Arsenic (III) oxide is not completely soluble in organics. As for the increase in the proportion of heptane together, in this case, the alcohol concentration decreases and the reaction rate, i.e. the duration of the process increases.

Example 1. In a flask with a Dean-Stark trap and reflux condenser protected by a calcium chloride tube, is boiled

0 suspension consisting of 87.45 g (0.30 mol) of antimony oxide (111), 19.78 g (0.10 mol) of mouse malleable anhydride, 53.37 g (0.720 mol) of butyl alcohol and 35 ml of heptane (volume ratio of RUN: heptane 2: 1) until complete elimination of water (4 h). Through nozzles Dean-Stark stood out 5.5 ml of water. After cooling, the alcohol-heptane phase is carefully separated by decantation and filtered, the precipitate is treated with 50 ml.

5 heptane and dried in a vacuum desiccator over phosphorus pentoxide and paraffin to constant weight. 87.27 g (0.299 mol) of antimony (III) oxide are obtained, which is 99.8% of the theoretical value.

0Found. %: Sb 83.67

SD203

Calculated,%: Sb 83,53

In order to regenerate the mouse for the covalent anhydride, the alcohol-heptaine filtrate is treated with 20 ml of bidistillo, and the next day the precipitate is filtered, washed with water and alcohol. As a result of air drying to constant weight, 17.80 g (0.090 mol) of arsenic (III) oxide are obtained as a white substance, which is 90% of the theoretical value.

Found%: As 75.31

Azaoz

Calculated,%: As 75,74

The volume of the separated mixture of butyl alcohol and heptane is 94.4 ml, which is 93.5% of the theoretical.

Examples 2-8. The processes were carried out analogously to example 1. The loading of the starting compounds and the yield of the target products are shown in the table.

From the examples and the table it can be seen that simplifying the process and increasing the degree of regeneration of the target products is provided by eliminating the staging, using a special installation and carrying out the process under more mild conditions. Increased yield is achieved by selective extraction.

arsenic (III) oxide, which is due to the use of butyl alcohols as the main part of the extractant.

Thus, the application of the proposed method allows to significantly simplify and intensify the process and increase the yield of target products by 30%.

Claims (1)

Claim 0 A method of separating antimony (III) oxides and arsenic (III) oxides, including treatment with an organic extractant, separating a mouse-containing extract, hydrolyzing it and drying oxides, 5 characterized in that, in order to increase the yield of products, the organic extractant is directly processed the initial mixture of antimony oxides and arsenic, as an organic extractant, use a mixture of butyl alcohol and heptane at a volume ratio of 2: 1, respectively, and the treatment is carried out at the boiling point of the suspension and until no more water vapor.